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US3796091A Expired / Lapsed US ⏱️ 0.0 years remaining

Borehole stress-property measuring system

Assignee: Individual
•
Filing: 1972-10-02
•
Granted: 1974-03-12
•
Expires: 1992-10-02
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Abstract

Abstract A stress-property measuring system for in situ determination of stress states and material properties of soil and rock media into which the apparatus is disposed via a borehole. The apparatus used in carrying out the instant method comprises two axiallyaligned cylindrical chambers. The first of said chambers is capable of exerting fluid pressure in a transaxial direction relative to the chamber and normal to the inner cylindrical surface of said borehole; the second of said chambers is completely unpressurized and pressure-insulated from said first chamber. Both chambers are fitted with a plurality of sets of diameter-measuring transducers for measuring changes in borehole diameter at a number of points in one diametrical direction along the borehole longitudinal cylindrical axis. Using this measuring device, stress state and material properties of surrounding ground medium may be determined as follows. Fluid pressure is introduced into said first pressurized chamber, and is varied through a gradient of ever-increasing pressures up to a predetermined pressure limit. These ever increasing pressurizations cause corresponding incremental changes in borehole diameters in various radial directions in both the pressurized and non-pressurized sections of said borehole, the magnitude of such changes being determined by the stress conditions and material properties of the surrounding medium. By measuring the diameter change indicated by said diametermeasuring transducers, sufficient and accurate data may be collected to enable computation of the various in situ stress states and material properties of the ground medium.

Inventors

  • 👤 S Serata

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-02 15:20
CPC Classifications
G; G01; G01N; G01N3/00; G01N3/08; G01N3/10; E; E02; E02D; E02D1/00; E02D1/02; E02D1/022; G01N33/00; G01N33/24

Claims Analysis

Total Claims: 14
Claim 1
Independent Claim 83 words
A method of analyzing stress states and material properties of ground media surrounding a borehole which consists of applying radially outward pressure to said borehole only along a first portion of the length thereof, positioning a plurality of transducers in said borehole transaxially of the length thereof in said first portion of the borehole and in a second portion of the length of said borehole adjacent said first portion, and measuring the radial deformation of said borehole in said first and second portions.
Claim 2
Independent Claim 83 words
A method of analyzing stress states and material properties of ground media surrounding a borehole which consists of applying radially outward pressure to said borehole only along a first portion of the length thereof, positioning a plurality of transducers in said borehole transaxially of the length thereof in said first portion of the borehole and in a second portion of the length of said borehole adjacent said first portion, and measuring the radial deformation of said borehole in said first and second portions.
Claim 3
Dependent Claim 43 words
The method of claim 1 in which said transducers lie in a plurality of diameter-axis planes in each of which a set of a number of said transducers are disposed to observe the distribution curve of the diameter change along the borehole axis.
Claim 4
Dependent Claim 30 words
The method of claim 1 in which said pressure is incrementally increased, and said measurements are taken during successive incremental increases in pressure with respect to time of the pressurizing.
Claim 5
Dependent Claim 36 words
The method as set forth in claim 1 in whIch said pressure is applied to said borehole substantially uniformly along said first portion while not permitting any such pressure to be applied along said second portion.
Claim 6
Dependent Claim 79 words
The method Of claim 4 in which said transducers are closely disposed in said borehole in said second portion starting immediately next to said first portion at an axial distance from said first portion no greater tHan twice the diameter of said borehole, so that the most critically changing portion of the diameter change distribution curve lies within the distance from the juncture of said portion twice the diameter of said borehole as observed in the individual diameter-axis planes.
Claim 7
Dependent Claim 80 words
Apparatus for analyzing stress states and material properties of ground media surrounding a borehole, comprising a first tubular member and an axially aligned second tubular member, said first member having a radially expandable outer portion, means for selectively expanding said portion, a plurality of transaxially disposed length-measuring devices carried by said first and second members and normally extending beyond the outer surfaces thereof, each said length-measuring device measuring the diameter of said borehole at the location of each said device.
Claim 8
Dependent Claim 80 words
Apparatus for analyzing stress states and material properties of ground media surrounding a borehole, comprising a first tubular member and an axially aligned second tubular member, said first member having a radially expandable outer portion, means for selectively expanding said portion, a plurality of transaxially disposed length-measuring devices carried by said first and second members and normally extending beyond the outer surfaces thereof, each said length-measuring device measuring the diameter of said borehole at the location of each said device.
Claim 9
Dependent Claim 21 words
Apparatus as set forth in claim 6 in which said length-measuring devices comprise transducers spaced axially of each of said members.
Claim 10
Dependent Claim 24 words
Apparatus as set forth in claim 7 in which said transducers are disposed in a common transaxial direction in a plurality of diameter-axis planes.
Claim 11
Dependent Claim 37 words
Apparatus as set forth in claim 7 in which said transducers have electrical leads extending through said first member, said first member having a pressure chamber therein, and means sealing said first member from said second member.
Claim 12
Dependent Claim 16 words
Apparatus as set forth in claim 7 in which said transducers comprise linear variable displacement transformers.
Claim 13
Dependent Claim 34 words
Apparatus as set forth in claim 6 in which said first and second members are secured together, and said first member has an inner fluid pressure chamber therein for expanding said expandable outer portion.
Claim 14
Dependent Claim 65 words
Apparatus as set forth in claim 11 in which said first chamber is substantially sealed by a partition wall which enables fluid pressure to be exerted on the surface of said borehole up to the extent of the first chamber and, at the same time, enables the said length-measuring devices of the second chamber to be disposed substantially immediately next to the limit of pressurization.

References Cited (Backward Citations)

US3364737A Cited
DE1298479B Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1977-03-11 1977-09-10 1978-03-12 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1981-03-11 1981-09-10 1982-03-12 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1985-03-11 1985-09-10 1986-03-12 $7700.00 Window Closed / Lapsed

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